Definition
2-Chloro-4-methyl-3-nitropyridine (2C4M3NP) is a nitropyridine derivative that could form an acceptor fragment of 2-adamantylamino-5-nitropyridine (AANP). This crystal shows a particularly large optical non-linearity. It is observed that the mean C-C (ring) bond distance calculated between the ring carbon atoms of 2C4M3NP is 1.387 Å. In X-ray data of pyridine, the mean C-C (ring) bond distance is 1.394 Å. The C-H bond distances are found to be 1.081 Å. The computed values of C-C (ring) and C-H are slightly higher than that of the experimental value. This is attributed to the substituents present in the pyridine. The C-C-C bond angle where the -Cl and -NO2 group is attached with the middle carbon is more than 120
? while the C-C-C bond angle where the -CH3 is substituted is less than 120
? in 2C4M3NP. The N-C-CH3 bond angle (116.3
。) is less than that of the C-C-CH3 (124.2
。) probably due to the weak hydrogen bond formed between the nitrogen and hydrogen of the methyl group[1].
References
[1] Arjunan, V. , et al. "A comparative study on vibrational, conformational and electronic structure of 2-chloro-4-methyl-3-nitropyridine and 2-chloro-6-methylpyridine." Spectrochimica Acta Part A Molecular & Biomolecular Spectroscopy 92.none(2012):305-317.
